Job: Five-time Tony Award-winning costume designer and chair of the American Theatre Wing. The North Carolina native is the visionary behind memorable costumes of Broadway blockbusters ranging from the “Chicago” revival to “The Producers” to “Nine.” The latter two garnered him Tony’s for best costume design.

One might say theater is in Long’s blood: His father was a professor and stage director at Winthrop University, and his mother was a high school theater teacher, actress and playwright.

After obtaining a degree in history from the College of William and Mary, Long studied set design at the Yale School of Drama. “I’m a frustrated architect,” he says. After graduating in 1975, he moved to New York and worked for couturier Charles James for three years.

His big break came in 1978, when a fellow Yalie, Karen Schulz, brought him on the Broadway show “The Inspector General” to do costumes. Since then, he’s crafted the clothes for 64 other Broadway productions, most recently “The Mystery of Edwin Drood,” which opened last week at Studio 54, and “Rodgers & Hammerstein’s Cinderella,” which goes up in January.

Work style: Long draws and paints in the basement of his studio, away from the hustle-bustle of assistants and interns working upstairs. “I work downstairs because I hate A/C,” he says, a nod to his upbringing in the hot, humid climate of the South. He spends many mornings tapping away correspondence on a green Remington typewriter for his responsibilities as the chair of the American Theatre Wing, a post to which he was appointed in June. “I don’t know how to turn on a computer, and I don’t have a cellphone,” jokes the Luddite. Each day, an assistant gives him a card printed with his day’s schedule of fittings, appointments and other social engagements that he tucks away in a pocket of his trademark navy blazer.

Office: Long’s studio, located on Walker Street in TriBeCa, has long been rooted in the entertainment business: The basement area was home in the mid-’90s to Blue Angel, a burlesque joint that reportedly attracted celebs such as Lou Reed and Drew Barrymore, who once performed a notorious striptease. Long relocated here from a Chelsea brownstone three years ago.

Off to the right in the foyer, a yellow “brag wall” is adorned with photos — including one of Long fitting Natasha Richardson for the 2005 revival of “A Streetcar Named Desire” — and costumes, such as the Pearl Girls dress from “The Producers” movie.

“My whole job is helping someone become someone else,” Long says as he poses in front of a full-length mirror next to a voluminous blue dress, one of his “Drood” creations.

On the first-floor, a fitting room is chock-a-block with racks of costumes from “Drood,” as well as stock, such as berets and other props from past productions. Mannequins sit atop tables, cloaked in some of Long’s most famous designs, like a lacy black filigreed bodysuit made for Anna Morris for “Nine.”

Decor: The walls of Long’s basement workspace are covered with rows and rows of costume sketches at various stages of their development: “Rodgers & Hammerstein’s Cinderella” sketches occupy the wall to the right; sketches, cast headshots and printouts of illustrations from “Drood” hang on the left. A bookshelf in the right-hand corner holds sketch books, watercolor trays and books about de Kooning.

Desk: Long paints under an incandescent light — to mimic stage lighting — at a large, square-shaped wooden table. The surface is covered almost entirely in typical artist ephemera — costume sketches, spools of thread in pink and gold, fabric swaths in a rainbow of colors, shimmering foils.

Routine: The designer is an early riser, often drawing and painting away in his basement studio by 5 or 6 a.m. on most weekdays, and very often on weekends. “I live here,” he says. “I feel like I never leave.” Long works on his designs for most of the morning, and actors and actresses begin to trickle in for fittings around 1 or 2 p.m. By 5 or 6 p.m., he’s off to city hot spots to hobnob with theater types over drinks and dinners.

Caffeine habit: A self-proclaimed coffee addict, Long frequents a Starbucks around the corner several times a day for a small coffee — always black.